The book talks about the feedback loop that happens when we hold or feed a baby, how they light up when we come to answer a cry, and we light up in return when we take care of them. I remember it so well-- even when I was half crazy with fatigue, how my kids would wiggle all over when I appeared. This is the beginning, according to the book, of our formation into creatures who can trust the outside world, and have real relationships. If things are askew at the light up and wiggle stage, there may be trouble later.
The book says that when we see something happen to another, something hurtful or joyful, we have a response in our physical selves, the mirror neurons fire to allow us to feel it also. We have known this since long before brain scans of course. Here is a quote from the 18th century:
'By the imagination we place ourselves in his situation, we conceive ourselves enduring all the same torments, we enter as it were into his body, and become in some measure the same person with him, and thence form some idea of his sensation, and even feel something which, though weaker in degree, is not altogether unlike them.'
Oddly that is Adam Smith, the economist. And he has it just right. The mirror neurons do give us the feelings of another, and they are indeed 'weaker in degree.' (Don't you just love how the enlightenment people were so unafraid to scatter their learning wide? A little poetry, a little math, a little flower picking, some metallurgy, not like now when we are limited by what we think we are.)
And it reminds me-- just after Hazel died I had an interaction with three little girls who live nearby. They were perhaps nine years old. I was outside and they came and asked after her. One came closer than the others, the speaker for them all. She had a plastic hula-hoop. I answered quietly that when we took her in for the broken leg she had turned out to be much much sicker than we knew, and that was why her bones broke, and that she had died. The little girls face wrinkled.
"Yes," I said
"So... She is all the way dead?"
And the child looked at me. She put her hand on her chest where her heart is, over her flat little girl chest.
"I feel your pain inside me as if it were my own," she said.
Wow. That is what the book is on about.